{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T17:28:26.234Z","years_from_j2000":26.678,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued J2000 position is carried along the great circle the object's own published motion puts it on, at a constant velocity, and the result is referred to the true equator and equinox of this instant. Those are separate things: the motion moves the object, and the rotation turns the grid under it by about fifty arcseconds a year, with nutation adding up to another seventeen.","excluded":"Parallax, the radial-velocity perspective term, aberration and refraction; each is below the accuracy of the catalogued positions themselves. An object with no published proper motion comes back where the catalogue has it rather than at a fabricated zero, and says so with a null pm_ra_mas_yr. A body with no fixed position is not propagated at all — its place comes from an ephemeris, which is what /api/v1/visible answers with."},"slug":"ngc-7688","name":"NGC 7688","class":"lenticular_galaxy_s0","category":"galaxy","object_type":"Lenticular galaxy S0","mag":15.4,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":352.7729166666667,"dec_deg":21.411527777777778,"epoch_ra_deg":353.108954,"epoch_dec_deg":21.559653,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Pegasus","discovered":"1865","featured":false,"url":"https://spacecatalog.org/object/ngc-7688","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.4,"h_mag":10.86,"j_mag":11.57,"k_mag":10.58,"hubble_type":"S0","wikidata_id":"Q1168702","discovered_by":"Christian Heinrich Friedrich Peters","ngc_type_code":"G","major_axis_arcmin":0.94,"minor_axis_arcmin":0.67,"position_angle_deg":95,"surface_brightness":23.89},"designations":[{"catalog":"2MASX","designation":"2MASX J23310424+2124232"},{"catalog":"2MASX","designation":"2MASX J23310547+2124412"},{"catalog":"LEDA","designation":"LEDA 71648"},{"catalog":"NGC","designation":"NGC 7688"},{"catalog":"PGC","designation":"PGC 71648"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-02T19:50:56.720Z","attribution":"Data from SpaceCatalog.org. Individual records carry their source and license in `source`; attribution is required for CC-BY and CC-BY-SA rows."}